As part of the further development of mobile radio from the GSM standard to EDGE or further on to the UMTS standard, new demands are being made on the transmission characteristics of power amplifiers. Previously, information was transmitted as pure phase information (GMSK), however, recent developments require that the amplitude be also evaluated for information transmission. This results in more stringent requirements for the transmission characteristics of power amplifiers. On the one hand the amplifier element must be linear, and on the other hand the transmission characteristics must not depend on temperature changes and operating voltage variations. However, this is not always the case using transistors. Often times linear and non-linear distortions need to be minimized. To achieve this, a pre-equalization in the base band or intermediate frequency or in the form of a closed loop such as a polar loop is implemented. However, in each case a significant balancing and/or circuit overhead is required with such an arrangement.
Accordingly, an efficient and cost-effective amplifier arrangement is needed.